Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity (measured in W/m2), in comparison to a reference level.
The measure of a ratio of two sound intensities is
where I1 and I0 are the intensities.
The sound intensity level is given the letter "LI" and is measured in "dB". The decibel is a dimensionless quantity.
If I0 is the standard reference sound intensity
(W = watt), then instead of "dB SPL" we use "dB SIL". (SIL = sound intensity level).
Read more about this topic: Sound Intensity
Famous quotes containing the words sound, intensity and/or level:
“But sound of water over a rock
Where the hermit-thrush sings in the pine trees
Drip drop drip drop drop drop drop
But there is no water”
—T.S. (Thomas Stearns)
“As siblings we were inextricably bound, even though our connections were loose and frayed.... And each time we met, we discovered to our surprise and dismay how quickly the intensity of childhood feelings reappeared.... No matter how old we got or how often we tried to show another face, reality was filtered through yesterday’s memories.”
—Jane Mersky Leder (20th century)
“For him nor deep nor hill there is,
But all’s one level plain he hunts for flowers.”
—Unknown. The Thousand and One Nights.
AWP. Anthology of World Poetry, An. Mark Van Doren, ed. (Rev. and enl. Ed., 1936)